You can pretty much patent anything. My sister is a patent litigator (in-court stuff, not just a high-falutin' patent clerk), and she frequently rolls her eyes at the stuff the PTO "certifies". This nonsense pays her rent, that's for sure. The old joke about Microsoft trying to patent ones and zeros isn't all that far off the mark.
When I looked at Bob's link, my reaction was "Oh, really? That's not going to do much." I was at NASA 40 years ago when they were testing aero on trucks. The biggest drag component was turbulence around the box and the gaps between the boxes. Solution? Round-off the corners, and a mere 6" radius did wonders.
So if UP wants to get meaningful gains, they need to design a nosecone system that fits over the ends of the boxes. Of course, the cost of applying/removing said nosecones exceeds the savings. For that matter, the extra handling cost and loss of capacity of putting the wedge on the front car definitely will not be made up in fuel savings. If they ran numbers on this thing and there was ROI, there must have been a lot of SWAG assumptions - we're talking 0.1% improvements, so small that a single made-up number can tweak results.